F15Rules Posted January 18, 2018 Author Share Posted January 18, 2018 1 hour ago, 25585 said: Thank you John, interesting comparison. I thought the Vixen had a flourite lens! As SW ED PRO models do, perhaps your 120 is a smidgeon closer to your Tak for that reason. Tak F7.5 seem to be ideal travel/grab scopes, while F9 is perhaps the "Home Not Away" one to own. All that remains is to compare a SW 100 ED PRO F9 doublet against a DL. The SW ED Pro has an FPL53 element, not Fluorite. The SW ED100 Pro F9 is a nice scope, but not in the same league as the Tak ☺. Dave Link to comment Share on other sites More sharing options...
F15Rules Posted January 18, 2018 Author Share Posted January 18, 2018 3 hours ago, John said: FrT Telescopes do an F/12.5 120mm ED doublet refractor. Quite expensive though: http://www.frtelescopes.com/frt120ded That's a beautiful scope John?. Lovely lines and colour. It's not cheap, but I guess if the lens is a good one...very much a niche player a la Skylight, but it's good to see small artisan companies like this.. thanks for the link ?. Dave Link to comment Share on other sites More sharing options...
25585 Posted January 19, 2018 Share Posted January 19, 2018 5 hours ago, F15Rules said: The SW ED Pro has an FPL53 element, not Fluorite. The SW ED100 Pro F9 is a nice scope, but not in the same league as the Tak ☺. Dave FPL53 (and 51) are synthetic flourite, so do count ? As to whether Taks ? are better, I hope one day to find out ????? Link to comment Share on other sites More sharing options...
Stu Posted January 19, 2018 Share Posted January 19, 2018 1 hour ago, 25585 said: FPL53 (and 51) are synthetic flourite, so do count ? As to whether Taks ? are better, I hope one day to find out ????? Synthetic being the operative word... Fluorite crystal does not scatter any light so a laser does not show when it passes through the Fluorite element. Not the same with FPL53 glass. https://www.cloudynights.com/topic/331900-fpl-53-green-laser-test/ 2 1 Link to comment Share on other sites More sharing options...
25585 Posted January 19, 2018 Share Posted January 19, 2018 (edited) 11 minutes ago, Stu said: Synthetic being the operative word... But does not mean lesser, or inferior. Quite the opposite possibly ? Who is it makes the lenses for Takahashi? ? https://www.geologyin.com/2015/10/why-do-fluorite-crystals-use-to-make.html Edited January 19, 2018 by 25585 Link to comment Share on other sites More sharing options...
Stu Posted January 19, 2018 Share Posted January 19, 2018 2 minutes ago, 25585 said: But does not mean lesser, or inferior. Quite the opposite possibly ? Certainly not the opposite. My understanding is that for doublets, using Fluorite makes a difference to the colour correction and contrast. It is certainly my experience from using my Tak that it performs better than previous scopes I've had so I'm happy with what I've got. For triplets I don't think it makes as much difference. None of this is to say that FPL-53 ED scopes are bad, they are not. The 100ED is still an excellent scope. 3 Link to comment Share on other sites More sharing options...
Stu Posted January 19, 2018 Share Posted January 19, 2018 9 minutes ago, 25585 said: Who is it makes the lenses for Takahashi? ? Canon as far as I'm aware. Why the devil icon? 3 Link to comment Share on other sites More sharing options...
Stu Posted January 19, 2018 Share Posted January 19, 2018 13 minutes ago, 25585 said: But does not mean lesser, or inferior. Quite the opposite possibly ? Who is it makes the lenses for Takahashi? ? https://www.geologyin.com/2015/10/why-do-fluorite-crystals-use-to-make.html I think you are confusing a synthetically grown crystal with synthetic Fluorite FPL-53 which is a glass not a crystal. 2 1 Link to comment Share on other sites More sharing options...
John Posted January 19, 2018 Share Posted January 19, 2018 1 hour ago, 25585 said: ...As to whether Taks ? are better, I hope one day to find out ????? I was a doubter until last year. They are. 5 1 Link to comment Share on other sites More sharing options...
GavStar Posted January 19, 2018 Share Posted January 19, 2018 (edited) Here is a table produced by TEC comparing the design specifications of fpl53 vs fpl55 vs fluorite options(shaded blue) for a TEC140. Edited January 19, 2018 by GavStar 2 Link to comment Share on other sites More sharing options...
25585 Posted January 19, 2018 Share Posted January 19, 2018 9 hours ago, Stu said: I think you are confusing a synthetically grown crystal with synthetic Fluorite FPL-53 which is a glass not a crystal. I yield to your greater knowledge ? but the article I linked to suggested to me at time of reading, that grown flourite crystals = synthetic. Had SW been using proper flourite, it would have been advertised. D'oh me! ? Link to comment Share on other sites More sharing options...
25585 Posted January 19, 2018 Share Posted January 19, 2018 (edited) 9 hours ago, John said: I was a doubter until last year. They are. I think a F7.5 100mm being light and short-ish would be a good spotting scope and telephoto lens (when camouflauged) as well as travel/g&g astro, so a DF is on my to-buy list for later. ? Edited January 19, 2018 by 25585 Link to comment Share on other sites More sharing options...
Stu Posted January 19, 2018 Share Posted January 19, 2018 22 minutes ago, 25585 said: I yield to your greater knowledge ? but the article I linked to suggested to me at time of reading, that grown flourite crystals = synthetic. Had SW been using proper flourite, it would have been advertised. D'oh me! ? I am a long way from being an expert, but I do read up on stuff when I need to refresh my memory. As you acknowledge, there is a difference between a synthetically grown Fluorite crystal, which is still a crystal vs a glass which contains a high level of fluorides but is still a super cooled liquid not a crystal. To say that FPL-53 is synthetic Fluorite is incorrect I believe, but it does have an Abbe number close to Fluorite. As an aside, synthetically grown Fluorite is favourable because natural Fluorite has too many flaws. Actually, it is not a case of Fluorite scope good, fpl scope bad, far from it. Many factors are important, the mating element material, the design, figure and polish of the elements, the cell design and manufacture etc etc. A number of high end manufacturers get this right. I happen to enjoy doublet scopes for observing, and in this case I believe that Fluorite allows for better colour correction and reduced scatter/increased contrast. I have had better views of Jupiter in the Tak than I had with a very good FPL-53 triplet so that satisfies me. This article may be of interest if you haven't already seen it. http://scopeviews.co.uk/What is Fluorite.htm 4 1 Link to comment Share on other sites More sharing options...
JeremyS Posted January 19, 2018 Share Posted January 19, 2018 2 minutes ago, Stu said: This article may be of interest if you haven't already seen it. Thanks for the link, Stu. It's a nice overview of fluorite lenses vs high spec glass materials, plus all the other considerations. I'm glad that Takahashi takes these worries away by providing their fluorite doublet series Jeremy 2 Link to comment Share on other sites More sharing options...
GavStar Posted January 19, 2018 Share Posted January 19, 2018 11 minutes ago, Stu said: I happen to enjoy doublet scopes for observing, and in this case I believe that Fluorite allows for better colour correction and reduced scatter/increased contrast. I have had better views of Jupiter in the Tak than I had with a very good FPL-53 triplet so that satisfies me. Stu, I find fluorite triplets work pretty well for observing as well ? 1 1 Link to comment Share on other sites More sharing options...
Stu Posted January 19, 2018 Share Posted January 19, 2018 6 minutes ago, GavStar said: Stu, I find fluorite triplets work pretty well for observing as well ? Especially big ones!!! 1 Link to comment Share on other sites More sharing options...
John Posted January 19, 2018 Share Posted January 19, 2018 45 minutes ago, Stu said: Actually, it is not a case of Fluorite scope good, fpl scope bad, far from it. Many factors are important, the mating element material, the design, figure and polish of the elements, the cell design and manufacture etc etc. A number of high end manufacturers get this right.... Indeed. My TMB / LZOS 130 uses neither Ohara FPL or Fluorite. LZOS use their own proprietary glass types (OK4 and OF-1) in their objectives and I believe don't make this available to any other optical manufacturer. The results judging from my example are very, very good 2 1 Link to comment Share on other sites More sharing options...
Moonshane Posted January 19, 2018 Share Posted January 19, 2018 I have only ever had one Vixen, a 80mm f11 achromat. It was beautifully made and with the 2" focuser. Really great for what it was but ED aperture won in the end. Incredibly light and sharp too. 6 Link to comment Share on other sites More sharing options...
mikeDnight Posted January 19, 2018 Share Posted January 19, 2018 22 hours ago, John said: Here is a short post I made on the CN forum comparing the two: https://www.cloudynights.com/topic/541112-vixen-ed102ss-and-takahashi-fc100dl-brief-comparison/ In early 2004 a friend bought a Vixen ED second hand and allowed me to play with it over a few nights. It was the longer version of Vixens 102 ED and it was very impressive. My friend however, always had a leaning towards the F6.5 version and not long after buying the long fl Vixen, an F6.5 came up for sale. He sold the first scope, much to my dissapointment, as obviously the shorter scope would be rubbish on the planet's as well as being riddled with CA. How wrong I was! We spent countless hours at the eye end of that Vixen ED, which gave some, not only memorable, but truly spectacular even jaw dropping views of DSO's and planets alike. Years earlier, an observing acquaintance stormed off in a blaze of fury, kicking his garden gate off its hinges, after my Vixen 102mm F13 achromat floored his much prized 8.5" Newtonian reflector, while observing Saturn. Soon after, his reflector came to some unfortunate end! Vixen seemed to me to be just as good as Tak when it came to their fluorite scopes, and they were seriously good across the board with their other refractors too. I've not yet had chance to look through their modern ED's, which I believe are Japanese optics, but I suspect they'll be excellent also! 3 Link to comment Share on other sites More sharing options...
25585 Posted January 19, 2018 Share Posted January 19, 2018 1 hour ago, mikeDnight said: In early 2004 a friend bought a Vixen ED second hand and allowed me to play with it over a few nights. It was the longer version of Vixens 102 ED and it was very impressive. My friend however, always had a leaning towards the F6.5 version and not long after buying the long fl Vixen, an F6.5 came up for sale. He sold the first scope, much to my dissapointment, as obviously the shorter scope would be rubbish on the planet's as well as being riddled with CA. How wrong I was! We spent countless hours at the eye end of that Vixen ED, which gave some, not only memorable, but truly spectacular even jaw dropping views of DSO's and planets alike. Years earlier, an observing acquaintance stormed off in a blaze of fury, kicking his garden gate off its hinges, after my Vixen 102mm F13 achromat floored his much prized 8.5" Newtonian reflector, while observing Saturn. Soon after, his reflector came to some unfortunate end! Vixen seemed to me to be just as good as Tak when it came to their fluorite scopes, and they were seriously good across the board with their other refractors too. I've not yet had chance to look through their modern ED's, which I believe are Japanese optics, but I suspect they'll be excellent also! I feel sorry for the poor Newtonian! ? 2 Link to comment Share on other sites More sharing options...
osbourne one-nil Posted January 19, 2018 Share Posted January 19, 2018 2 hours ago, John said: Indeed. My TMB / LZOS 130 uses neither Ohara FPL or Fluorite. LZOS use their own proprietary glass types (OK4 and OF-1) in their objectives and I believe don't make this available to any other optical manufacturer. The results judging from my example are very, very good My Vixen only has FPL53 glass - I feel cheated. 1 1 Link to comment Share on other sites More sharing options...
Stu Posted January 19, 2018 Share Posted January 19, 2018 8 minutes ago, osbourne one-nil said: My Vixen only has FPL53 glass - I feel cheated. Link to comment Share on other sites More sharing options...
RT65CB-SWL Posted January 19, 2018 Share Posted January 19, 2018 On 15/01/2018 at 16:03, Fozzie said: I can join in with this... my vixen GP.. won't say much about it other than she's well travelled and well loved.. especially now.. Ta Fozzie Nice legs! 1 2 Link to comment Share on other sites More sharing options...
Stu Posted January 19, 2018 Share Posted January 19, 2018 1 minute ago, Philip R said: Nice legs! Agreed. Not a great actress though, a bit wooden..... Sorry. It's Friday... 1 4 Link to comment Share on other sites More sharing options...
25585 Posted January 19, 2018 Share Posted January 19, 2018 32 minutes ago, Stu said: Agreed. Not a great actress though, a bit wooden..... Sorry. It's Friday... It a-pier-s so ? 3 Link to comment Share on other sites More sharing options...
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